This patent is directed to a dynamic balancer for a vibratory apparatus and a method for balancing a vibratory apparatus, and, in particular, to a dynamic balancer for a vibratory screening apparatus and a balancing method for the same.
For many years, mining operations have used brute force vibratory screening units to separate the materials generated by upstream crushing and/or grinding operations so that these materials may be further processed downstream to extract metal from ore. A brute force, or direct drive, screening unit is one in which the exciter is secured or bolted to the trough (or driven mass). Such units housed in large processing buildings or plants have been used to process, for example, 1000 tons/hour of rock to separate out the desired amount of metal.
Coincident with the recent introduction and commercialization of large capacity grinding mills, lower quality ore bodies are being processed. This results in considerably more material being processed to obtain the same amount of metal from higher quality ore bodies. As a consequence, these direct drive units have had to handle significantly more material, with processing rates doubling or tripling as a result.
To handle the increased processing demands, the industry has seen a shift to larger and larger units. Where a direct drive unit screening unit with a 2 meter width may have been used in the past, a direct drive unit with a 4 meter width is used now to accommodate the increased loading. Increases in size have associated and related increases in the power requirement for the screening unit.
Unfortunately, direct drive units dampen under load. That is, as the loading increases, the stroke of the unit decreases. As a further consequence, more of the energy of the screening unit is directed through the drive bracket into the side panels. This can lead to premature failure of the apparatus and loss of available processing time and resultant revenues while increasing the required maintenance time and costs.